1. Field of the Invention
The present invention relates to an image forming apparatus in which writing apparatus data is written into a nonvolatile memory.
2. Description of the Related Art
In a typical current image forming apparatus, when apparatus data is changed, the changed apparatus data is written into a volatile memory (e.g. a synchronous dynamic random access memory (SDRAM)), with a copy also being written into a nonvolatile memory (e.g. a flash read only memory (ROM)).
Each time the apparatus data is changed, the apparatus data is written into the flash ROM. Therefore, the number of flash ROM writing operations reaches the limit of rewritable times of the flash ROM before the image forming apparatus itself reaches the end of its product life cycle; thus, the flash ROM may not be able to retain the apparatus data. In an attempt to solve this problem, one known image forming apparatus writes change data into the volatile memory, and then the change data written in the volatile memory is written into the flash ROM only at a predetermined time periods. However, if the apparatus data is frequently changed, the writing of the next change data may occur while the change data is being written into the flash ROM because writing into the flash ROM takes some time. In this case, the next change in apparatus data may not be written correctly. Therefore, there is a demand for an image forming apparatus capable of writing a change in apparatus data into the nonvolatile memory while reducing the number of writing operations with respect to the nonvolatile memory.